Police have charged Robert Wayne Gladden Jr., 15, with attempted first-degree murder and assault in connection with Monday’s shooting at Perry Hall High School in Baltimore County.

Gladden has been charged as an adult, police said. He is being held without bail at the Baltimore County Detention Center. Police will hold a news conference Tuesday morning to discuss the case.

Daniel Borowy was shot in his back shortly before 11 a.m. in the school’s cafeteria, court documents said. Eyewitnesses described hearing a sound like a bag of chips popping before realizing that someone was shooting.

Bowery, 17, remains in critical condition.

With heightened security and trauma counselors on hand, Perry Hall restarted its school year Tuesday, the day after a student shot in the cafeteria was left in critical condition and another student was taken into custody as the suspected gunman.

The shooting took place on the first day of classes Monday as several hundred students were in the cafeteria, where the sound of gunfire initially seemed like just another piece of the aural landscape.

Instead, it was gunfire, striking Bowery, who was airlifted to Maryland Shock Trauma Center as classmates and strangers offered prayers for him at impromptu gatherings and across social media. Police said they do not believe the victim was targeted by the shooter.

Witnesses said a school counselor quickly grabbed the shooter and pinned him up against a vending machine. The suspect was taken into custody shortly after the shooting.

A man who identified himself as the suspect’s father told the Associated Press that his son had been bullied but declined to give further details. A woman who said she was related to the father gave the following statement on the family’s behalf: “We are horrified. We did not see this coming and our thoughts and prayers are with the victim and the victim’s family.”

Students described a day that suddenly turned chaotic during an early lunch break in the cafeteria of the school, the county’s largest with nearly 2,200 students. Rather than the festive atmosphere of a school community returning after summer break, police helicopters whirred overhead, students dove under cafeteria tables and, as the news spread quickly, distraught parents tried to reach their children, in person or by phone or text message.

Throughout the day, a sense of disbelief pervaded.

Jeremy Knavel, 16, said he couldn’t believe his eyes when he saw a student emerge from a bathroom Monday morning, taking a gun out from under his shirt.

“I thought it was a joke,” he said. “Then when I heard the shot, I ran. I’m shaken still. I can’t believe it actually happened.”

Sophomore Nick DiPaula, 15, said he and a friend were talking in the cafeteria when they heard a loud bang and turned to see what it was.

“We just see him with the gun, and he’s aiming it at my table,” DiPaula said.

A school counselor he identified as Jesse Wasmer ran over and tackled the gunman as he and other students hit the floor and another teacher started yelling, “Get out of the building, get out of the building!” DiPaula said.

Wasmer was hailed as a hero by colleagues and across the Internet, where a “Thanks Mr. Wasmer” Facebook page was created. He could not be reached to comment, and school officials declined to discuss details of the incident.

The actions of Wasmer and other teachers in the cafeteria who intervened “were really beyond what anyone can be expected to do,” and “made that situation the best it could have been in such a horrible time,” said Matt Smoot, a science teacher in his fifth year at the school.

New Baltimore County schools Superintendent Dallas Dance, on his first day of classes after being hired this spring to head the school district, praised the school’s “heroic, brave faculty.”

Dance said Perry Hall High would be open Tuesday with additional security at the school. The Police Department’s Critical Incident Stress Debriefing team will provide support for students and faculty, Armacost said.

Junior Ryan Brady, 15, said he was several feet away from the shooting victim and saw blood on his shirt. As the counselor was tackling the shooter, his gun went off again, the bullet hitting the ceiling, said Brady, who got under a table to hide.

“After I got outside, my hands were shaking really bad,” he said. “First thing I did was call my mom and told her everything that happened, and told her I was all right.”

Police officers were already at the school, standard procedure for the first day of classes. County Executive Kevin Kamenetz said police and school officials responded in “terrific fashion” to the shooting.

Students were escorted to the nearby Perry Hall Shopping Center at the corner of Ebenezer and Belair roads, where parents were instructed to meet them, police said. Hundreds of visibly shaken parents and others gathered at the shopping center as police helicopters hovered overhead.

* Many of his profile pictures show Gladden taking photos of himself while his long hair covers his face. Gladden also claims to like musicians Marilyn Manson and Slipknot and references notorious mass murderer Charles Manson.

* Gladden’s Facebook page first caused concern yesterday when parents of students at the school noticed Gladden’s last status update read “First day of school, last day of my life. t(~_~t), fu*k the world.” .

* Gladden’s classmates confirmed Tuesday to The Associated Press that the page belonged to the suspected gunman.

* Police told The Associated Press that Gladden came to school armed with a disassembled shotgun and 21 rounds of ammunition. He also reportedly had a bottle of vodka.

* Gladden’s father confirmed his son had been bullied prior to the shooting. However, police have not officially released a motive.

* Students discussing the shooting on Tumblr offered different opinions of Gladden. After reading his Facebook page, one student, identified only as username those-atomic-bombs, said “any sympathy I had for this kid now gone until further notice.”

* However, a student identified by the name -dazzleme- said Gladden “isn’t a psycho, or a monster or anything that you may think he is,” adding Gladden didn’t mean to shoot Borowy. “I know Bobby and he isn’t the type of kid to just go and randomly shoot people. He’s the kid that makes you laugh. He was bullied often and I believe that he just could not take it anymore,” -dazzleme- wrote on the Tumblr feed.

Sad, the kid sounds deeply troubled. Our prayers are with Daniel Borowy and his family. We pray he will fully recover.